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-rw-r--r--src/shared/machine-id-setup.c61
1 files changed, 43 insertions, 18 deletions
diff --git a/src/shared/machine-id-setup.c b/src/shared/machine-id-setup.c
index 3efba03..1a63794 100644
--- a/src/shared/machine-id-setup.c
+++ b/src/shared/machine-id-setup.c
@@ -5,6 +5,7 @@
#include <sys/mount.h>
#include <unistd.h>
+#include "sd-daemon.h"
#include "sd-id128.h"
#include "alloc-util.h"
@@ -12,6 +13,7 @@
#include "creds-util.h"
#include "fd-util.h"
#include "id128-util.h"
+#include "initrd-util.h"
#include "io-util.h"
#include "log.h"
#include "machine-id-setup.h"
@@ -46,13 +48,22 @@ static int acquire_machine_id_from_credential(sd_id128_t *ret) {
return 0;
}
-static int generate_machine_id(const char *root, sd_id128_t *ret) {
+static int acquire_machine_id(const char *root, sd_id128_t *ret) {
_cleanup_close_ int fd = -EBADF;
int r;
assert(ret);
- /* First, try reading the D-Bus machine id, unless it is a symlink */
+ /* First, try reading the machine ID from /run/machine-id, which may not be mounted on
+ * /etc/machine-id yet. This is important on switching root especially on soft-reboot, Otherwise,
+ * machine ID may be changed after the transition. */
+ if (isempty(root) && running_in_chroot() <= 0 &&
+ id128_read("/run/machine-id", ID128_FORMAT_PLAIN, ret) >= 0) {
+ log_info("Reusing machine ID stored in /run/machine-id.");
+ return 1; /* Indicate that the machine ID is reused. */
+ }
+
+ /* Then, try reading the D-Bus machine id, unless it is a symlink */
fd = chase_and_open("/var/lib/dbus/machine-id", root, CHASE_PREFIX_ROOT | CHASE_NOFOLLOW, O_RDONLY|O_CLOEXEC|O_NOCTTY, NULL);
if (fd >= 0 && id128_read_fd(fd, ID128_FORMAT_PLAIN | ID128_REFUSE_NULL, ret) >= 0) {
log_info("Initializing machine ID from D-Bus machine ID.");
@@ -61,9 +72,8 @@ static int generate_machine_id(const char *root, sd_id128_t *ret) {
if (isempty(root) && running_in_chroot() <= 0) {
/* Let's use a system credential for the machine ID if we can */
- r = acquire_machine_id_from_credential(ret);
- if (r >= 0)
- return r;
+ if (acquire_machine_id_from_credential(ret) >= 0)
+ return 0;
/* If that didn't work, see if we are running in a container,
* and a machine ID was passed in via $container_uuid the way
@@ -103,7 +113,7 @@ static int generate_machine_id(const char *root, sd_id128_t *ret) {
int machine_id_setup(const char *root, bool force_transient, sd_id128_t machine_id, sd_id128_t *ret) {
const char *etc_machine_id, *run_machine_id;
_cleanup_close_ int fd = -EBADF;
- bool writable;
+ bool writable, write_run_machine_id = true;
int r;
etc_machine_id = prefix_roota(root, "/etc/machine-id");
@@ -141,13 +151,14 @@ int machine_id_setup(const char *root, bool force_transient, sd_id128_t machine_
if (sd_id128_is_null(machine_id)) {
/* Try to read any existing machine ID */
- if (id128_read_fd(fd, ID128_FORMAT_PLAIN, ret) >= 0)
- return 0;
+ if (id128_read_fd(fd, ID128_FORMAT_PLAIN, &machine_id) >= 0)
+ goto finish;
- /* Hmm, so, the id currently stored is not useful, then let's generate one */
- r = generate_machine_id(root, &machine_id);
+ /* Hmm, so, the id currently stored is not useful, then let's acquire one. */
+ r = acquire_machine_id(root, &machine_id);
if (r < 0)
return r;
+ write_run_machine_id = !r;
}
if (writable) {
@@ -185,11 +196,13 @@ int machine_id_setup(const char *root, bool force_transient, sd_id128_t machine_
run_machine_id = prefix_roota(root, "/run/machine-id");
- WITH_UMASK(0022)
- r = id128_write(run_machine_id, ID128_FORMAT_PLAIN, machine_id);
- if (r < 0) {
- (void) unlink(run_machine_id);
- return log_error_errno(r, "Cannot write %s: %m", run_machine_id);
+ if (write_run_machine_id) {
+ WITH_UMASK(0022)
+ r = id128_write(run_machine_id, ID128_FORMAT_PLAIN, machine_id);
+ if (r < 0) {
+ (void) unlink(run_machine_id);
+ return log_error_errno(r, "Cannot write %s: %m", run_machine_id);
+ }
}
/* And now, let's mount it over */
@@ -207,6 +220,9 @@ int machine_id_setup(const char *root, bool force_transient, sd_id128_t machine_
return r;
finish:
+ if (!in_initrd())
+ (void) sd_notifyf(/* unset_environment= */ false, "X_SYSTEMD_MACHINE_ID=" SD_ID128_FORMAT_STR, SD_ID128_FORMAT_VAL(machine_id));
+
if (ret)
*ret = machine_id;
@@ -237,7 +253,7 @@ int machine_id_commit(const char *root) {
etc_machine_id = prefix_roota(root, "/etc/machine-id");
- r = path_is_mount_point(etc_machine_id, NULL, 0);
+ r = path_is_mount_point(etc_machine_id);
if (r < 0)
return log_error_errno(r, "Failed to determine whether %s is a mount point: %m", etc_machine_id);
if (r == 0) {
@@ -265,7 +281,12 @@ int machine_id_commit(const char *root) {
fd = safe_close(fd);
/* Store current mount namespace */
- r = namespace_open(0, NULL, &initial_mntns_fd, NULL, NULL, NULL);
+ r = namespace_open(0,
+ /* ret_pidns_fd = */ NULL,
+ &initial_mntns_fd,
+ /* ret_netns_fd = */ NULL,
+ /* ret_userns_fd = */ NULL,
+ /* ret_root_fd = */ NULL);
if (r < 0)
return log_error_errno(r, "Can't fetch current mount namespace: %m");
@@ -284,7 +305,11 @@ int machine_id_commit(const char *root) {
return log_error_errno(r, "Cannot write %s. This is mandatory to get a persistent machine ID: %m", etc_machine_id);
/* Return to initial namespace and proceed a lazy tmpfs unmount */
- r = namespace_enter(-1, initial_mntns_fd, -1, -1, -1);
+ r = namespace_enter(/* pidns_fd = */ -EBADF,
+ initial_mntns_fd,
+ /* netns_fd = */ -EBADF,
+ /* userns_fd = */ -EBADF,
+ /* root_fd = */ -EBADF);
if (r < 0)
return log_warning_errno(r, "Failed to switch back to initial mount namespace: %m.\nWe'll keep transient %s file until next reboot.", etc_machine_id);
generated by cgit v1.2.3 (git 2.39.1) at 2024-07-13 08:04:15 +0000